I am also having this problem right out of the gate with Imoen. I am able to level her up to level 7 and dual class her, but then the first level in which she gets a proficiency, I am stuck at the level up screen.
Separately, the game is crashing for me when I attempt to level up Jaheira.
I have a relatively lightly modded game: Ascension, Wheels of Prophecy, Rogue Rebalancing, Monk Overhaul, cdtweaks, Talents of Faerun, SCS, atweaks, Hidden Gameplay Options. I installed all the components for ToF and SCS. I am playing on Mac OS X.
I will give this a try again without Rogue Rebalancing and Monk Overhaul, and see if that makes a difference.
